I think they're pretty blunt as to "why." What they seem to be hazy on is the "how."
Why give that up when the customer is really only going to use bluetooth audio anyway? Anyone who cares enough about navigation is gonna use an app on their phone. Native car navigation is a superficial value-feature not a use feature.
The edge that Carplay gets is really minimal. I'm repulsed by the new car market, its many multiples over-connected anyway. When it comes to digital features my gut says only the safety ones drive sales.
I thought the same thing until I owned an EV. Using the car's navigation is essential for road trips that involve charging along the way. Maybe some day Google Maps et al. will gain access to API's to read the car's current charge and enough information to accurately predict charge along the route, but for now I have completely changed away from using 3rd party nav and rely only on the native vehicle nav.
Sounds like a problem that will get solved automatically once charging stations are as common as fuel pumps.